Automatic releasing switch



Oct. 18,1927. 7 A. R. CURTIS AUTOMATIC RELEASVING SWITCH Filed Dec. 28.1923 IIIIlIIIIIIIIIIIIIl/Ir I i mam:

Patented Oct. 18,1927.

UNITED STATES ARTHUR R. CURTIS, OF CLEVELAND, OHIO.

-v 1,646,189 PATENT o F ca- AUTOMATIC RELEASING swircn.

Application filed December 28,1923. Serial no. 683,207. 7

a compact simple and inexpensive device having few parts, and theseparts of simple construction.

In addition to the features of simplicity, compactness and cheapness' ofmanufacture, the present invention also embodies to a high degree theadvantageous features of extreme sensitiveness and reliability inoperation.

With the above and other objects in view. the invention may be said tocomprise the device illustrated in the "accompanying drawings, describedin the following specification and particularly set forth inthe appendedclaims, together with such variations and modiiications thereof as willbe apparent to those skilled in the art to which the inventionappertains.

Reference should be had to the accompanying drawings forming a part ofthis specification in whichFig. 1 is a vertical section taken in a planewhich includes the axis of the'solenoid and showing the sup porting baseand switch thereon in elevation; Fig. 2 is a section taken on l1116'220fFig. 1; Fig. 3 is a plan view of the base;

Fig. 4 isa horizontal section taken on line 4 -4 of Fig.1; Fig. 5 isahorizontal sectiontaken on line 55 of Fig. 1; Fig.6 is a horizontalsection taken on line-66- of'Fi'g. 1; Fig. 7 is a vertical section ofthe base taken on line 77of Fig; 3;'F1g. 8 is a sectional detail viewshowing the blade operatin push button and connection to'the blade."Feferring to the accompanyingdrawing,

the. entire switch releasing mechanis'niis ;mounted within a relativelysmall casing which has a base 1. of insulating material adapted to beattachedin verticalposition to a suitable support. The base 1 15provided with an outstandinglledge 2 along its edges *fformed-toreceivefthe flangesof an enclosing cover3 which is attachedto the base 1by means of a post 4 whichhas a threaded inne'r end moulded into thecentral portion ofthebase, the cover 3 being-secured to'the "outer endof the post by means of a screw 1 5 passing through the cover the endofthe post. I V

The circuit controlling switch isin the form of a knife switch mounteddirectly upon the base 1 and provided with a'blade b'wlilc ll ls pivotedbetween the outwardly extending flanges of a pair of angle clips 7 and 8which are secured to the base 1 by means of the binding screw 9." Thesuper-- posed flanges of the clips which lie upon, the base being heldagainst turning 'movej ment thereonby means of a ledge 10 formed on thebase; :The pivot for the blade 6 is formed by striking up a tongue 11from the outwardlyextending flange. of one of the supporting clips. Thistongue 11 passes and tapped into I through an opening in the blade 6 andinto an opening 12 formed in the other clip. The

fixed contact of the switch is formed bya pair of angle clips 13and. 14which are superposed one upon the other with their outwardly extendingflanges spaced suiiicie'ntly to permit'the blade 6 to be receivedbetween them. T he angle, clips 13 and 14 are secured to the base bymeans of a binding screw 15. At their ends the outwardlyextendingflanges are curvedoutwardly at 16 and 17 to permit the blade tobe inserted between the flanges and. to guide the blade into the spacebetweenthe flanges. outer angle clip 13 is of relatively light Theresilient sheet metal while the'inner angle Y clip 14 is heavier andless' resilient. The blade'is thus pressed yieldingly against the .heavycontact member 14 in its movement into and out of engagement therewith;The; outwardly extending flange of the light clip I 13 terminates shortof the outer end of the outwardly extending flange of the clip 14 sothat the break always occurs between the knife and the heavier contactmemberso that the spring contact member is'notdamaged bythe arcing whichoccurs when the circuit 1SbIOk6I1L I The Invotedblade 6 is urgedoutwardly by means of a spring 18 which is formed of spring wire, thefree ends of which are bent outwardly at 19 and secured in recesses inthe base 1 and the body of Which is bent to substantially circular form,the Wire straddling the knifeblade and pivot support and beingjloopedunder'the knifeblade iii-"an advance of its pivotp The spring'18 servesto release the switch with a' snap whenever the blade-is released fromits holding means.

The upper end of the blade '6 is provided with a T head formedby ahardened steel end piece which is engaged by the hook 21 of a gravitylatch member 22 which serves to hold the knife blade in circuit closingposition. The latch 22 is in the form of a flat plate and the hoopportion 21 thereofis formed by fianging the outer edge of the plate toprovide an inclined edge portion against which the end of the bladestrikes inmoving to .closed position to push the latch out of the way asit passes the hook portion. The inner edge of the latch plate engages ina slot 23 in thebase '1 immedi- .ately above tllEfiXGLl contact members13 and 14, the latch plate being held from movement out of the slot bymeans of a projection 24 integral with the heavier of the contactmembers 14 and extending upwardly through a slot in the latch plate. 22.The project-ion 24 serves to loosely retain the latch plate inthe slot,and the latch plate swings downwardly by gravity into retainringengagement with theend 2O ofthe blade.

Thelatch 22 is adapted to be actuated by means of a push button 25'slidably mounted in the casing. The push button has an inner reducedend 26 which is slldably mounted in a recess formed in the base 1 andits outer end isslidably mounted. in the cover 3. Adjacent its inner endthe push button 25. is provided with a shoulder 27 which engages with anupwardly projecting tongue 28 struck up from the body of the ingmaterial. The ,upper end of the coil I with by the gravity latch 22.

leased, the latch 22 drops by gravity to positionin which it will engageand retain the blade when the same is again moved to closed position.Forreturning the blade to closed position, it is provided with a pushbutton 29 in the inner end of which is imbedded a strap 30 which has alaterally benttongue 31 at itsinner end which ex tends through anopening 32 in the blade. lVhen the push button 29 is pushed inwardly theblade is moved into engagement with the contact and retained inengagement there- Mounted alongside t-he'pivoted blade 6 and closelyadjacent thereto is a solenoid 33.

which is woundabouta tube 34 of insulatis connected'to the binding screw15 and the lower end of the coilis connected to a binding screw 35, theexternal circuit being connected to the device through the bindingscrews 9 and 35. \Vithin thetube 34 there is :a soft iron core orstrikermember 36 which has a head portion 37 at its upper I nected.

adjustable plug 39 which has a threaded engagement with the tube at itslower end. The plug 39 is so positioned thatthe upper end oi the corepro cc'tsa short dlstance into the interior of the solenoid. By properlyadjusting the plug 39, the core 36 may be so positioned that it will belifted b the solenoid when a desired predetermined current passesthrough the solenoid. As the core 36 moves upwardly in the solenoid itmoves into the magnetic field so that a progressively increasing forceis exerted thereon impartinga sharp acceleration to the core in itsupward movement, causing it to strike theextension 37 of. the latchplate with a sharp impact, swinging the latch plate upwardly out ofengagement with the knife plate which when so released instantly springsto open posit-ion breaking the circuit.

Having described my invention, I claim:

An automatic releasing switch having a casing consisting of a base and acup shaped cover adapted to be secured to the ba'se,'a switch mounted onthe base and having a fixed contact member and a movable contact memberbiasedtoward open position, a latch movably mounted on the base andengagecable with the movable contact member to hold the same inengagement with the fixed contact, said latch having a bias toward itsengaging position, said latch having a laterally extending portion, avertically disposed ,tube oi: insulating material detachably secured atits lower end to the cover and positioned within the same alongside theswitch and beneath the laterally extending portion of the latch, asolenoid supported on said tube, said solenoid having a core'within thetube which isv adapted to be actuated to strike said laterally extendingportion of the latch torelease the latch upon passage of a predeterminedcurrent through the solenoid, an'd'terminals on said base to whichtheopposite ends :ofthe solenoid winding are con- 2. An automaticcasingcons stmg ofa base and a cup shaped cover adapted to be secured tothebase, a

switch mounted onthe baseand having a fixed contact member and a movablecontact member biased towardopen'position, a latch movably mounted onthe baseand-engage- A able with the movable contact member ;to

hold thev same in engagement with the fined contact, said latch having abias toward its engaging position, said latch having a laterallyextending. portion, a tube of insulating releasing switch having amaterial which is interiorly threaded at its lower end, means forrigidly securing said tube to the bottom wall of the casing com-v uponthe upper end portion of the tube, and

having a. retaining portion at its outer edge;

7 gaging position.

a core within the tube which normally rests on said plug and extendsinto the lower portion of the winding, said laterally extending portionof the latch lying over the upper end of the tubewhen the latch is incontact en- 3. An automatic releasing switch comprising a casing havinga base adapted to be secured in vertical positionupon a support, a knifeswitch having a vertically disposed blade which is pivoted at its lowerend, a spring pressing said blade outwardly, a fixed contact in the formof angle clips secured to the base and having closely adjacent outwardlyextending flanges adapted to receive the blade bet-ween them, ahorizontal groove in the base above the clips, a latch plate having itsinner edge seated in the groove, said plate having a slot and one of theclips having an extension passing through the slot and serving to holdthe plate loosely in the groove whereby the plate is pivotally supportedin the groove, said latch plate extending laterallyto one side of theswitch and en gageable with the upper edge of the blade, said platehaving a lug projecting upwardly therefrom, a push button having ashoulder engageable with the lug whereby the latch plate may be moved bythe push button to release the blade, and a magnetically actuatedstriker adapted to engage the laterally extending portion of the blade.

4. An automatic releasing switch having a casing consisting of a baseand a cup-shaped cover adapted to be secured to the base, a

' switch mounted on the base having a fixed contact member, a movablecontact member biased toward open vposition, a latch movably mounted onthe base and engageable with the movable contact member to hold the samein engagement with the fixed contact, said latch having a bias towardits engaging position, a tube of insulating material mounted in verticalposition beneath said latch, said tube being interiorly threaded at itslower end, means for rigidly securing said tube to the bottom wall ofthe casing comprising a threaded plug screwed into the lower end of thetube and extending through saidbottom wall and a clamping nut on saidplug outside the casing, a solenoid supported upon the upper portion ofthe tube, and a core within the tube which normally rests on said plugand extends into the lower portion ofthe winding.

5. An automatic releasing switch comprising a casing having a base, aknife switch a slot and one of the clips having an extension passingthrough the slot and serving to hold the plate loosely in thegroovewhereby the plate is pivotally supported, said latch plate extendinglaterally to one side of the 7 switch and having a retaining portion atits outer edge engageable with the upper edge of the blade, said platehaving a projecting lug, a push button engageable with the lug to movethe latch plate in a direction to release the blade, and a magneticallyactuated striker adapted to engage the laterally extending portion ofthe blade.

' In testimony whereof, I hereunto affix my i signature. 7 p

V ARTHUR R. CURTIS.

